Elastic-fluid turbine.



No. 858,860; YPATENTED JULY 2, 1907,

. e. UALBU.

BLASTIG FLUID TURBINE. AHLIQATIOR FILED NOV. 26, 1906 INVENTOR WITNESSES yma oo TTORNEY GUSTAF DALEN,

OF STOCK HOLM, SWEDEN, ASSIGNOR TO DE LAVAL STEAM TURBINE COMPANY.

. ELASTIC-FLUID TURBINE.

Specification of Letters Patent.

'ratented July 2, 1907.

Application filed e b 26, 1906. Serial No. 345,051.

To all whom it may concern:

Be it known that I, GUSTA'E DhLriN, a subject of the King of Sweden, residing at Stockholm, Sweden, have invented a certain new and useful Improvement in Elastic-Fluid Turbines, of which the following is a specification.

The invention relates to elastic fluid turbine wheels, and more particularly to the construction of the buckets and the arrangement thereof in a turbine of the radial flow type, wherein the buckets protrude into the space between the face of a rotor disk and the opposing face of a stator; the working fluid passing between said faces and acting upon concentric rings of rotor buckets and concentric rings of stator buckets alternating therewith.

The buckets are preferably formed with a shank, a head and an intermediate working portion, integrally from a suitably shaped bar. The working portion, the concave surface of which receives the working fluid, is preferably produced by cutting away the material of the bar and its resulting cross section is therefore less in area than that of either head or shank, and in addition its edges are protected, as hereinafter explained. The buckets are disposed in the grooves with the shank and head concavity of one fitting the shank and head convexity of the next, so as to fill said grooves, and may be provided with securing means.

In the accompanying drawings Figure 1 is a side elevation of one of my buckets, Fig. 2 is an end view, Fig. 3 shows the arrangement of the buckets on the rotor and stator, Fig. 4 is a section on the line A. B. of Fig. 3; Fig. 5 is a section on the line C. D. of Fig. 3; Fig. 6 shows, in diametral section, half of a rotor with its associated casing and steam passages, Fig. 7 .is a view similar to Fig. 3, showing a mode of securing the buckets in the grooves of the rotor and stator and also the bands for uniting the buckets of each concentric circular row.

Similar numbers of reference indicate like parts.

The buckets are cut in suitable lengths from bars of metal having a cross section of substantially the shape shown in Figs. '2 and 4. Each bucket has a shank 1 of the normal cross section and a working portion 2 formed by cutting away the material to produce a cross section substantially as shown in Fig. 7 and in dotted lines Fig. 2. The cut away portion 2 is preferably located (as shown in Fig. 1) so that a head 3 is left beyond it. The concave surface 11 of the working portion 2 receives the working fluid.

In Fig. 6, 4 is the rotor shaft, 5 the rotor disk and 6 the stator, which may be part of the rotor casing. Upon a face of the rotor disk and upon the opposing faces of v the stator are formed a plurality of concentric grooves.

In these grooves are inserted the shanks 1 of the buckets.

As shown in Fig. 4, said shanks fit closely one against the other so that each circular row of buckets completely fills the holding groove. The relative position of the grooves in rotor disk and stator is such that the circular rows of buckets in the rotor disk face alternate with the circularrows of buckets in the stator face, the protruding portions of said buckets extending into the space between rotor face and stator face. Thus the rows 7, 8 of buckets in the face of rotor 5 alternate with the rows 9, 10 of buckets in the face of stator 6. The buckets in the rotor face have their fluid receiving surfaces 11 all turned in the same direction. The buckets in the stator have their fluid receiving surfaces 12 all turned in the opposite direction.

The working fluid may be admitted as indicated by the lower arrow in Fig. 6 between the hub of the rotor disk and the stator and will then pass outward to exhaust in a direction radial to the rotor disk, acting upon the rotor buckets to turn the rotor disk, and being deflected by the intermediate fixed stator buckets so as to strike the rotor buckets at suitable angles. If desired the annular passage between rotor face and stator face, in which the buckets are located, may increase in cross section outward as shown in Fig. 6 and in such case the lengths of the buckets will be increased; and correspondingly the lengths of the working portions 2, and hence of the fluid receiving surfaces 11, will be correspondingly enlarged. Thus the working portion of the outermost pair of bucketsfbetween lines a. -b.) is obviouslylonger than the working portion of the next pair of buckets (between lines a. (1.). The rows of buckets may also be arranged in groups with steam spaces between them. Thus, in Fig. 6, there are three groups 13, 14, 15 with intermediate steam spaces 16.

The buckets of each concentric row may be secured in their groove in any suitablemanner. One way is to form inside the groove and in one wall thereof a channel 17, and then, as each bucket is inserted in place, to strike up from the material thereof by means of a hammer and chisel, a projection 18 entering said groove.

In order to prevent loosening of the buckets, they may be provided with recesses on the outer sides of their heads, in which recesses may be laid encircling secureach groove fit closely together, they unitedly form substantially a solid ring in the wall, of which the several Working portions 2 form a continuous working passage for the fluid, said passage containing fluid receivingpartitions with surfaces 11, 12.

I claim:

1. A turbine bucket having a shank and a working portion, the said working portion being substantially crescentshaped in cross section, and the said shank having longitudinal projections with outer faces extending laterally beyond the longitudinal edges of said working portion.

2. A turbine bucket having a concave-convex shank and a concavo-convex working portion, the concavity of said working portion being similar to and in prolongation of the concavity of the shank, the convexity of said shank projecting beyond the convexity of said working portion, and the said shank having longitudinal projections with outer faces extending laterally beyond the longitudinal edges of said working portion.

A turbine bucket having a shank, a head and a working portion between said shank and head, the said working portion being substantially crescent-shaped in cross sec tion and the said shank and head having longitudinal pro jeetions with outer faces extending laterally beyond the longitudinal edges of said working portion.

4. A turbine bucket having a concavo-convex shank, a coneavoconvex head and a concave-convex working por tion between said shank and head, the concavity of said working portion being similar to and in prolongation ol. the concavities of head and shank, and the convexities of head and shank projecting beyond the convexity olf said working portion.

5. In a turbine, a support having a groove and a plurality 01' buckets having shanks constructed to enter said groove and disposed successively in contact, the said groove being provided with a recess and a portion ol the material of the buckets being struck up to enter said recess.

6. In a turbine, a support having a groove, a plurality of buckets having concavo'eonvex shanks with lateral projections provided with outer bearing surfaces eonstructed to enter said groove and disposed therein suecessively in contact. the said bearing surt': es meeting the walls of said groove and the convexity of each bucket: be ing received in the cavity of the next adjacent. bucket.

7. In a turbine, a support: having a circular groove. a plurality of buckets each having a shank. a head and a working portion between said shank and head, the said shanks being constructed to enter said groove and being disposcd successively in contact, and the said heads havi a recesses, and a circular band disposed in said head recesses and connecting together said buckets.

In witness whereof, the applicant's signature. is hereunto atlixed in the presence ot' two witnesses.

GUSTAV llAliIdN.

Witnesses \l'aiinniuu Boxux, 'l. EknnonM. 

